Rear wheel cassette, hub and speed set compatibility question

Question

My bike's rear wheel was recently stolen so I am looking to replace it with a second hand one now. However I don't have much experience/knowledge about speed gear and cassette compatibility. My bike is a Giant Escape 2, 2013 model (Hybrid road bike). My drivetrain is a Shimano Tiagra 3x10 (don't know which series, bought this is a second hand bike). My rear wheel was a 700c. My questions are:

1- Would any Shimano 10 cassette work with my Tiagra 10-speed drivetrain? Does the wheel hub need to be compatible with the chosen cassette?

2- Would a Shimano 8/9 cassette work with this speed set (possibly with a fewer selection of speeds) if the derailleur screws are adjusted correctly?

3- Is there anything else one needs to take into account when replacing a rear wheel?

I checked the official Shimano documentation for these parts (3700 series) but could not see any cassette compatibility information. I have also checked some other topics in this forum such as 9 Speed Shimano cassette on 10+ speed hub which mostly seem to deal with hub and cassette compatibility. I wanted to double check as there doesn't seem to be very detailed answers in these topics about derailleur and cassette compatibility and does not exactly match my situation. Thanks

Answer 1

Hello and sorry to hear your wheel got stolen.

First consideration to make is whether you will be buying a second hand wheel with the cassette already fitted or buying a wheel and cassette separately. If you are buying the wheel with the cassette already on it, then you only need to worry that the wheel fits your frame and cassette works with your derailleur. If you are buying them separately then you need to also worry about hub to cassette interface.

Anyway, here we go. Things to consider in no particular order.

Wheel to frame compatibility

You wheel will need to have the right diameter. As you stated you have 700 wheels, so look for a 700 wheel to replace it. Smaller wheel will also fit but will look rather comical if you keep your original front wheel.

You wheel will also need to have the correct interface to fit the frame. Could be quick-release or through axle. Check your frame, identify the type, go with the right one.

Your new wheel will have to be designed for correct type of brakes (Disk/Rim). Note that these are not cross-compatible. Do not attempt to use disk brake wheels with a rim brake bike.

Last but not least your wheel will have to have correct size/spacing to fit your frame chainstays. This is important to get right and is whole subject in itself. For your convenience: AASBHTA

And finally it is a bonus if you can get hold of a wheel with similare rim width (inner/outer) to your front one. This will save you the hassle of fitting matching tires to front/reare wheels in the future. Note that rim width does not have to exactly match between front and rear wheel, it just has to be close within few mm.

Hub to cassette compatibility

This is only relevant if you are buying the cassette separately

There are currently three most commonly used interfaces: Shimano Hyperglide, Shimano Microspline and Sram XD. There are others but your are unlikely to come across them if you are looking to match a Tiagra... Check specifications online, go with the correct interface.

For compelteness I will mention that there is a consideration of hub width and how wide of a cassette it can accommodate. This is specific to Shimano Hyperglide. Some hyperglide hubs will only fit up to 10 speeds and will not fit 11- or 12-speed cassettes. This should not be a concern for you.

Cassette to derailleur compatibility

First and foremost, your new cassette must be 10-speed if you want to keep your old derailleur and shifter working correctly. No exceptions on this one.

Mixing cassettes from different manufactureres is a minefield. Up to 9 speeds you could safely mix shimano and SRAM, but from 10 onwards it gets progressively worse. I would recommend sticking with Shimano 10-speed cassette or looking for an aftermarket cassette (Sunrace or similar) that has a reputation of working with Shimano 10-speed derailleurs.

Last thing to consider is the size of your derailleur cage and its ability to accomodate largest cassette cog. This is not an issue if you are swapping like for like, but can become a problem if you try to stick an MTB cassette onto a bike with short cage road derailleur.

Answer 2

"Would any Shimano 10 cassette work with my Tiagra 10-speed drivetrain? Does the wheel hub need to be compatible with the chosen cassette?"

In most cases, yes, most any Shimano 10-speed cassette will work with your Tiagra drivetrain. There may be limits based on your rear derailleur's capacity and your current chain length. If you acquire a similar (gearing) sized 10-speed cassette from what you lost, you should be fine. Be aware that a Shimano 10-speed cassette needs a 1.0mm spacer put on the freehub first before sliding on the cassette to the freehub (this spacer comes with a new 10-speed cassette if it requires it).

The wheel hub (aka the freehub) does need to be compatible with the chosen cassette. If the freehub is Shimano 8/9/10 compatible, then just the 1.0mm spacer goes on first before the cassette. If the freehub is Shimano 11-speed compatible, then an additional spacer is required. The 11 speed freehub is 1.85mm wider than an 8/9/10, and therefore you would need to put the 1.85mm spacer on the freehub, then add on the 1.0mm spacer on top of the 1.85mm one (total of 2.85mm of spacers) before putting on the 10-speed cassette. If you acquire an 11-speed compatible wheel and you did not get a 1.85mm spacer with it, they are readily available at any bike shop as it is a relatively common part.

"Would a Shimano 8/9 cassette work with this drivetrain (possibly with a fewer selection of speeds) if the derailleur screws are adjusted correctly?"

This one is easy. The answer is no. Stick with 10-speed unless you were planning on changing your rear shifter too.

Art Gertner added good information on ensuring that the wheel hub (what fits between the rear dropouts, the interface between your "wheel" and your frame) is the correct width and is set up to handle a disc rotor if you have disk brakes. A wheel hub on the rear of a road bike can be different widths based on the configuration.